In order for a viewer to feel hyper-reality, a field of view above at least 30° is necessary, and an image display apparatus having a large field of view is necessary. Such kind image displays are disclosed in the following references.
(A) Japanese Patent Publication No. 2002-148711
(B) Toshiki Nagumo, “A Study of an Electric Power Plant Training Environment Using a Small Cylindrical Screen”, The Virtual Reality Society of Japan, Vol. 4, No. 3, pp 521-529 (1999)
In these references, an image is projected onto a screen having a spherical surface. By viewing from a concave side of the screen, the image can be displayed by wide field of view on the screen. In this case, in order for a viewer not to view aliasing (distortion) on the image projected onto the screen, the image is processed by aliasing-compensation before projection (Especially, in the reference (A)). However, in order to reduce the aliasing and maintain resolution of the image, for example, a plurality of projectors is necessary. In this case, the image display apparatus is complicated and the cost increases.